Not recognizing external hard drive

I'm having a similar problem. I have a WD 500GB external HD, formatted for Mac. Now the HD doesn't show up in Finder anymore.

Disk Utility sees the HD but it is greyed and named "disk2s2" instead of its name.

The options Mount and Eject are not greyed in Disk Utility.

When I click Mount, the option goes grey for a split second and Mount is back to active again, but nothing happens.

When I click Eject, Disk Utility takes 1 minute and then an error message appears, saying the disk couldn't be ejected. Close all applications... bla bla bla... But no file on the HD is selected or used by any other application. Only Disk Utility and Finder (of course) are open.

I ran a Verify Disk: it says "[name of disk] appears to be OK".

But the disk is still "disk2s2" in Disk Utility and it doesn't show up in Finder.

I don't know why Disk Utility recognises the name and sees there's a HD plugged in, but still greyes it out as "disk2s2".

I ran a Repair Disk: Disk Utility is now performing the "Updating boot support partitions for the volume as require" step. It says Estimate time: 2 minutes, but it's been stuck there for about 10 minutes. Should I keep waiting??

Disk Utility sees my HD "499.41 GB WD My Passport 070A ...." not greyed and Formatted: Mac OS Extended (Journaled). Then below I see the greyed "disk2s2" (not the disk name) and all the specifications are "-"

The files on the HD are still few (good thing I hadn't filled up the HD yet) and I guess I'll live without them. But I really wonder if I could make the HD show up again because clearly, Disk Utility still recognises it.

Thank you for any help/suggestions!

Update...

After about an hour of hanging with "Updating boot support..." in Disk Utility, I clicked Stop Repair and unplugged the HD.

Replugging it still gave the same problem (showed up in Disk Utility but not in Finder), so I restarted the MacBook Pro and ta-dah.... the HD is back as normal.

I have no idea what has happened. Sorry I cannot be of help if others have the same or similar problems.

(I'm on a Sep. 2009 MacBook Pro 13" 2.26 GHz Intel Core 2 Duo, Mac OS X (10.6.7), 2 GB 1067 MHz DDR3 NVIDIA GeForce 9400M)

I'm not sure what all of the various problems consist of, but my solution and saving grace was Tuxera NTFS for Mac. Give it shot and let me know if it worked.

Western Digital Drives Only. 1 Terrabyte My Book FYI Had to go to bottom of last menu, Support Menu, Legacy Products. I suggest that user's go to your own MFG's Website and search. Align Product, OS, and antiviral software recommendations while doing installs and reboots. Unblock applications seeking Internet access. Go!

http://wdc.custhelp.com/app/answers/detail/a_id/1164/related/1/session/L2F2LzEvd GltZS8xMzI2MzIzMjUwL3NpZC82dmo0blZOaw%3D%3D

OK, how about this:

I have a '97 Macbook connected directly via Ethernet cable to a brand new iMac (both running Lion 10.7.3)... Connected to the Macbook via Firewire is a WD 500Gb hard drive (own power supply, FAT32) and connected to the WD hard drive via Firewire is an 80Gb Macally HD (powered from USB on Macbook, Mac OS Extended (Journaled)).

The problem is... I can see both the WD and the Macally hard drives on the Macbook, but I can only see the Macally hard drive on the iMac. Both computers are set up to share and I login to the Macbook using the same profile I have logged into the iMac with (from the Finder window).

It is not a cable problem as both external drives are visible on the Macbook and the Macbook and Macally HD are visible on the iMac.

It is not a low power problem as both external drives have their own power sources.

Is it a driver problem? The iMac is basically a copy of what was on the Macbook (I used Migration Assistant to copy the entire computer) so why does the iMac not "see" the WD?

Please help?

Why does the iMac not 'see" the WD?

You are not going to believe me, because I didn't believe it either, but if I can

tell you, you at least will have something to work with that may help you.

First, let's dispell one thing that you are holding dear, and it's this:

"It is not a low power problem as both external drives have their own power sources."

Ready?

One of the power sources is not the correct one, or is and oldie and moldy one and needs to be renewed or refreshed with a new one.

What?

I did this myself. I spent a day and a half installing drivers, reinstalling software, switching cables, mildly pulling my hair out until at last resort, I called WD. The prompts got me through to the

right person for my product. Very nice, cooperative, understanding, sympathetic even.

I was out of warrantee over four years, but the technical support guy told me he's been approved to send me a new power supply, no charge.

After exhausting every techincal trick I knew in the book, reading the correct support sites, and ending up doing the suggestions at the WD website, installing things, and checking cables and connections more than once, I finally surrendered and called technical support.

Please allow three to five days for delivery.

As it was being shipped, I muttered to myself I had the right power supply connected. I kept all of them in a container with my other cameras, digital tablets, old computers and video cameras. I could see the device in the trouble shooter software I used, and the light was on, on the drive. I knew it was fine in there. What would a power supply have to do with it?

It had a whole lot to do with it, as I found out when it arrived..

Five days later it showed up. I plugged it in, booted it, it reinstalled the usb driver and presto change-o, the thing came up without me doing anything. (Did I mention, I rebooted several times, in an order manner, earlier?).

I don't know why, I had a 12v power supply on the external drive, but the tech seemed to have a suspicion that this was the problem, and it was. Maybe they have product support calls and cases on the computer there, and he read that with my product, it turns out to be ninety nine percent of the time, the faulty power.

Funny thing, they sent it to me gratis, free. If I can ever, ever, say a nice word about WD I will say it here:

WD knows what they are doing. Their phone system got me to the right guy. I kept a case number.
Shipping was fast. I called them back and thanked the same guy too.

He was happy. I was happy. Change your faulty power supply with a new one; you'll be happy.

My issue:

Wife's laptop wouldn't reboot after updating Safari, iTunes, and some other things. Latest updates. 13" 2011 Macbook Pro with Lion upgraded from Snow Leopard some time last summer. Screen would go grey with a revolving graphic and a progress bar, then the computer would shut off.

Tried booting to console recovery and do an fsck -fy. Couldn't repair volume. Tried graphic recovery boot with same result.

Decided to reinstall from Time Machine backup. Couldn't see how to get network connected. Got external drive off of Time Capsule that had backup and connected it to laptop and booted to recovery partition. Time Machine couldn't see hard drive. Frustrating.

Inserted Lion install disk that came with computer. WiFi, external drive both worked. Re-installed from backup.

It seems you need the install disk to have your graphical recovery console work properly.

My generic hard drive also failed to work, having read through this and several other threads as the cheapest and least disruptive, ie reinstalling op system (this is apple guys) the fault had to be with the external drive

I came across Funkin's response re their WD drive.

I took the part number from old power supply transformer and google soon found me a replacement under £9.00 arrived in two days and Hey presto my external drive now works. 🙂

Cheap resolution to a failed external. Under £9.00 to replace on a 5 year old external.

Thank you Funkin.

Well i was having the same issue i have a wd 1 tb my passport i use as my time machine well like a week ago it just stoped working my mac book pro wouldn't recognise it so i tred and tried odd thing was that it was showing on disc utilityes but not in the finder so after reading this section y plug it in one more time and just unplugged it without unomunting the drive and bamm i got my drive back..weird..

l_echeverri, and others, just for the record, I diconnected my Wester Digital (WD) external Passport drive again and again, and even without a Y cable (USB booster cable), it suddenly was recognized by my MAC (OSX10.6.8).

I guess it has something to do with me skyping WD Support, or vudoo. To support that, WD support guy said to me that it can take time for some macs to recognized the drive and assign proper power to it. Here's a snippet from WD Knowledgbase, too, which supports that:

Mac OSX can read FAT32 drives, however it may take up to 10 minutes (usually much less time is needed) for the OS to evaluate the volume and determine how to interact with it upon initial installation. If you wish, you can wait for the drive to be recognized, at which time the drive will function correctly. The advantage of this format is that the drive should also work on a PC.

I believe formatting the drive in Mac format and using Time Machine could help too, but I'm not willing to loose the compatibility with my PC, yet.

Supplemental: I recognize this problem as something which occurs after diconnecting the drive for long periods of time from my mac. I'll examine this issue further, and will update if I have new info.

Bottom line: Never loose hope.